Marina Axle U Bolts
Moderators: ClaytonSpeed, balmy
- jiversteve
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Marina Axle U Bolts
Does anyone have any dimensional information on the different sizes of U Bolts that attach the axle to the spring.
They get neglected and are subject to road dirt and corrosion.
Is there a common source of supply please?
They get neglected and are subject to road dirt and corrosion.
Is there a common source of supply please?
Not a Marina owner, built in 1985 from a 1974 1.8TC MOT failure.
See Marlin History.
http://www.5speedmarina.com
Type 9 gearbox, Vented front discs, Dolly Sprint axle with disc conversion.

Next project? Megajolt?
See Marlin History.
http://www.5speedmarina.com
Type 9 gearbox, Vented front discs, Dolly Sprint axle with disc conversion.

Next project? Megajolt?
- MarinaCoupe
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- Location: Bedford
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Re: Marina Axle U Bolts
Steve - Marinamadbaz had some made up a little while ago, send him a PM.
Chris
Chris
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Chicken Hawk
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Re: Marina Axle U Bolts
I have always used Escort MK1 U bolts with no issues
- jiversteve
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- Joined: Tue Jul 29, 2008 5:30 pm
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Re: Marina Axle U Bolts
It was my belief that Ford U-Bolts were all a larger diameter thread, so spring hangers had to be drilled. Also isn't the curve slightly different?
The following is my interpretation from the Earlpart Catalogue with what I think are the correct numbers.
Standard Marina U bolts
21H5242 U bolt & locking nuts, leaf spring, 2 leafs, Marina (5-3/16” Long) £7.90
21H5828 U bolt & locking nuts, leaf spring, 3 leafs, Marina POA
21H5957 U bolt & locking nuts, leaf spring, 4 leafs, Marina (5-7/8” Long) £7.90
21H5958 U bolt & locking nuts, leaf spring, use with wedge, Marina (6-1/2" Long) £11.43
They sound expensive if that is the price for a single U-bolt and not a set of four.
I don't trust their sizes, where were they measured from, the Axle center (the straight section) or the inside of the bend, or from the centre line of the bend. Its only a small difference but it would be important depending on the length of the thread etc.
I was hoping to find a supplier of various sizes so that different lowering blocks could be used.
The following is my interpretation from the Earlpart Catalogue with what I think are the correct numbers.
Standard Marina U bolts
21H5242 U bolt & locking nuts, leaf spring, 2 leafs, Marina (5-3/16” Long) £7.90
21H5828 U bolt & locking nuts, leaf spring, 3 leafs, Marina POA
21H5957 U bolt & locking nuts, leaf spring, 4 leafs, Marina (5-7/8” Long) £7.90
21H5958 U bolt & locking nuts, leaf spring, use with wedge, Marina (6-1/2" Long) £11.43
They sound expensive if that is the price for a single U-bolt and not a set of four.
I don't trust their sizes, where were they measured from, the Axle center (the straight section) or the inside of the bend, or from the centre line of the bend. Its only a small difference but it would be important depending on the length of the thread etc.
I was hoping to find a supplier of various sizes so that different lowering blocks could be used.
Not a Marina owner, built in 1985 from a 1974 1.8TC MOT failure.
See Marlin History.
http://www.5speedmarina.com
Type 9 gearbox, Vented front discs, Dolly Sprint axle with disc conversion.

Next project? Megajolt?
See Marlin History.
http://www.5speedmarina.com
Type 9 gearbox, Vented front discs, Dolly Sprint axle with disc conversion.

Next project? Megajolt?
- ClaytonSpeed
- FMM Site Admin

- Posts: 5140
- Joined: Thu May 31, 2007 12:17 pm
- Location: 4 Counties: North Warwickshire / South Derbyshire / Staffordshire / Leicestershire
Re: Marina Axle U Bolts
These are the ones I use for car axles and lowering blocks:
http://morrisminorspares.co.uk/shop/pro ... 1f364cd67b
http://morrisminorspares.co.uk/shop/pro ... 1f364cd67b
'73 MG Marina Turbo Saloon - Back on the road with T16 turbo power
'72 TC Coupe' 'SLK' - 1950cc - Asleep - possible retirement project E.T.A 2049
'72 TC Coupe' 'SLK' - 1950cc - Asleep - possible retirement project E.T.A 2049
- jiversteve
- Posts: 1141
- Joined: Tue Jul 29, 2008 5:30 pm
- Location: Spain
Re: Marina Axle U Bolts
Thanks Ben, I had no idea that the Morris Minor parts were so similar.
It's time to chase some more parts books.
The 2" longer ones look most appealing, but 2" longer than what?
More homework needed, if I want to identify the original part used on a Marlin Roadster.
It's time to chase some more parts books.
The 2" longer ones look most appealing, but 2" longer than what?
More homework needed, if I want to identify the original part used on a Marlin Roadster.
Not a Marina owner, built in 1985 from a 1974 1.8TC MOT failure.
See Marlin History.
http://www.5speedmarina.com
Type 9 gearbox, Vented front discs, Dolly Sprint axle with disc conversion.

Next project? Megajolt?
See Marlin History.
http://www.5speedmarina.com
Type 9 gearbox, Vented front discs, Dolly Sprint axle with disc conversion.

Next project? Megajolt?
Re: Marina Axle U Bolts
I've got Mk1/2 Escort ones on the estate and, although the curve is pretty close (I found the legs splayed out slightly, suggesting a slightly tighter radius), they are definitely a bigger diameter and need the spring plates opening out. Not a major hardship and gives you plenty more options once it's done! I had to go out and buy a drill specifically as I didn't have the right one so I know I had to do it.
I thought the minor ones (as Ben has shown) were too small a diameter, but he has lowered more cars than me so I'm probably wrong there!
I thought the minor ones (as Ben has shown) were too small a diameter, but he has lowered more cars than me so I'm probably wrong there!
Matt
1974 1973 Tundra Black Tulip 1800 SDL TC Estate "Mud"- slowly slowly coming together.
1972 White 1800 DL Saloon- Better than it looks, but it looks awful...
1974 1973 Tundra Black Tulip 1800 SDL TC Estate "Mud"- slowly slowly coming together.
1972 White 1800 DL Saloon- Better than it looks, but it looks awful...
- ClaytonSpeed
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Re: Marina Axle U Bolts
The Minor ones are the same diameter as Marina ones, the radius is also the same. I last used a set on a Mk3 with 2" lowering blocks. There was plenty of thread left over so I trimmed them to suit.
'73 MG Marina Turbo Saloon - Back on the road with T16 turbo power
'72 TC Coupe' 'SLK' - 1950cc - Asleep - possible retirement project E.T.A 2049
'72 TC Coupe' 'SLK' - 1950cc - Asleep - possible retirement project E.T.A 2049
- marinabuoy
- Posts: 317
- Joined: Tue Mar 26, 2013 6:38 pm
Re: Marina Axle U Bolts
Just ordered a couple of sets of these bolts from ESM, £3 each plus postage. Set that includes lowering blocks is £36 which means you're paying £12 per block, which seems expensive enough for a lump of metal that I'm guessing would need altered anyhow before it'll fit? Reckon it's not hard to fabricate blocks from odds in scrap box.
- ClaytonSpeed
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Re: Marina Axle U Bolts
These are the blocks I've bought in the past:
http://www.rallydesign.co.uk/advanced_s ... 40&x=0&y=0
http://www.rallydesign.co.uk/advanced_s ... 40&x=0&y=0
'73 MG Marina Turbo Saloon - Back on the road with T16 turbo power
'72 TC Coupe' 'SLK' - 1950cc - Asleep - possible retirement project E.T.A 2049
'72 TC Coupe' 'SLK' - 1950cc - Asleep - possible retirement project E.T.A 2049
- marinabuoy
- Posts: 317
- Joined: Tue Mar 26, 2013 6:38 pm
Re: Marina Axle U Bolts
Worthwhile saving on blocks there, haven't decided yet whether to go for !.5" or 2.0", I'll see how much I can get on front first just winding down adjusters without changing splines. Good website too, worth having a good look around, cheers.
- jiversteve
- Posts: 1141
- Joined: Tue Jul 29, 2008 5:30 pm
- Location: Spain
Re: Marina Axle U Bolts
OK thanks for all your help. I have tried to document this, primarily for Marlin owners but I am sure it will be useful to a marina/Ital owner one day.
If I have made any mistakes, or you can add something please let me know.
Possibly the most neglected part of a Mk2 Roadster are the four U Bolts securing the rear Axle to the leaf spring pads. They are subject to corrosion and road dirt, and in my experience rarely checked during routine maintenance. Often, when I have been changing rear axles, despite a liberal soaking in PlusGas they have sheared, or the thread is so corroded that it no longer offers proper security.
I believe that the original Marlin Kits were supplied with special U bolts, much longer than standard to allow for the tapered lowering blocks which are much thicker than those of the Marina 7CWT Van.
Replacing these U bolts is a comparatively easy task, but sourcing replacements was difficult when I first searched. Unfortunately I did not keep detailed information of my findings.
There are commonly available U bolts in many different lengths from Ford cars but these have a slightly larger diameter thread, so to fit them, all the spring plates need enlarging, 24 holes in all and the bolts stretched into position.
Below is a list, with as much information as I can trace of the available 3/8” U bolts.
Clearly the Morris 1000 SUS755 or SUS756 are probably the best alternatives for a Marlin Roadster as the excess length can be easily cut off, but I cannot claim to have used either.
Morris/Austin Marina
Parts as listed by EarlParts http://www.earlpart.co.uk/ but I have added the Marina Part Numbers.
These seem to me to be expensive for a set as they imply their cost is per U bolt.
Please note that the Marina wedge is substantially thinner than the Marlin item.
21H5242 (SUR214) U bolt & locking nuts, 2 leafs, Marina (5-3/16” Long)
21H5828 (SUR215?) U bolt & locking nuts, 3 leafs, Marina
21H5957 (SUR216) U bolt & locking nuts, 4 leafs, Marina (5-7/8” Long)
21H5958 (SUR217) U bolt & locking nuts, Use with Marina wedge, Marina (6-1/2" Long)
Morris Minor
Parts as listed by Morris Minor Spares http://morrisminorspares.co.uk/ Unfortunately they do not list overall lengths.
SUS728 U bolt & locking nuts, 5 leafs, Morris 1000
SUS729 U bolt & locking nuts, 7&8 leafs, Morris 1000
SUS755 U bolt lowering Kit 1 1/2” Note: Spacers may not fit Marina or Marlin
SUS756 U bolt & locking nuts, Morris 1000 Lowered Rear (Up To 2" Lower)
I did trace one manufacturer of these U bolts, A.R.B http://www.a-r-b.co.uk/ They are manufacturers of spare parts but deal with trade only, though they did supply to me.
If I have made any mistakes, or you can add something please let me know.
Possibly the most neglected part of a Mk2 Roadster are the four U Bolts securing the rear Axle to the leaf spring pads. They are subject to corrosion and road dirt, and in my experience rarely checked during routine maintenance. Often, when I have been changing rear axles, despite a liberal soaking in PlusGas they have sheared, or the thread is so corroded that it no longer offers proper security.
I believe that the original Marlin Kits were supplied with special U bolts, much longer than standard to allow for the tapered lowering blocks which are much thicker than those of the Marina 7CWT Van.
Replacing these U bolts is a comparatively easy task, but sourcing replacements was difficult when I first searched. Unfortunately I did not keep detailed information of my findings.
There are commonly available U bolts in many different lengths from Ford cars but these have a slightly larger diameter thread, so to fit them, all the spring plates need enlarging, 24 holes in all and the bolts stretched into position.
Below is a list, with as much information as I can trace of the available 3/8” U bolts.
Clearly the Morris 1000 SUS755 or SUS756 are probably the best alternatives for a Marlin Roadster as the excess length can be easily cut off, but I cannot claim to have used either.
Morris/Austin Marina
Parts as listed by EarlParts http://www.earlpart.co.uk/ but I have added the Marina Part Numbers.
These seem to me to be expensive for a set as they imply their cost is per U bolt.
Please note that the Marina wedge is substantially thinner than the Marlin item.
21H5242 (SUR214) U bolt & locking nuts, 2 leafs, Marina (5-3/16” Long)
21H5828 (SUR215?) U bolt & locking nuts, 3 leafs, Marina
21H5957 (SUR216) U bolt & locking nuts, 4 leafs, Marina (5-7/8” Long)
21H5958 (SUR217) U bolt & locking nuts, Use with Marina wedge, Marina (6-1/2" Long)
Morris Minor
Parts as listed by Morris Minor Spares http://morrisminorspares.co.uk/ Unfortunately they do not list overall lengths.
SUS728 U bolt & locking nuts, 5 leafs, Morris 1000
SUS729 U bolt & locking nuts, 7&8 leafs, Morris 1000
SUS755 U bolt lowering Kit 1 1/2” Note: Spacers may not fit Marina or Marlin
SUS756 U bolt & locking nuts, Morris 1000 Lowered Rear (Up To 2" Lower)
I did trace one manufacturer of these U bolts, A.R.B http://www.a-r-b.co.uk/ They are manufacturers of spare parts but deal with trade only, though they did supply to me.
Not a Marina owner, built in 1985 from a 1974 1.8TC MOT failure.
See Marlin History.
http://www.5speedmarina.com
Type 9 gearbox, Vented front discs, Dolly Sprint axle with disc conversion.

Next project? Megajolt?
See Marlin History.
http://www.5speedmarina.com
Type 9 gearbox, Vented front discs, Dolly Sprint axle with disc conversion.

Next project? Megajolt?
Re: Marina Axle U Bolts
I've got a set from somewhere that are for a smaller diameter axle, they can't be minor ones then! Can't remember where the blocks I'm using came from. I'll be removing them shortly anyway as I've got decambered springs to go on post rebuild.
Matt
1974 1973 Tundra Black Tulip 1800 SDL TC Estate "Mud"- slowly slowly coming together.
1972 White 1800 DL Saloon- Better than it looks, but it looks awful...
1974 1973 Tundra Black Tulip 1800 SDL TC Estate "Mud"- slowly slowly coming together.
1972 White 1800 DL Saloon- Better than it looks, but it looks awful...
- MarinaCoupe
- Posts: 10257
- Joined: Thu May 31, 2007 5:26 pm
- Location: Bedford
- Contact:
Re: Marina Axle U Bolts
Matt possible an Anglia or early Cortina?
Chris
Chris
- ClaytonSpeed
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- Joined: Thu May 31, 2007 12:17 pm
- Location: 4 Counties: North Warwickshire / South Derbyshire / Staffordshire / Leicestershire
Re: Marina Axle U Bolts
Chris,
What u bolts did you use on your pickup when you lowered it?
What u bolts did you use on your pickup when you lowered it?
'73 MG Marina Turbo Saloon - Back on the road with T16 turbo power
'72 TC Coupe' 'SLK' - 1950cc - Asleep - possible retirement project E.T.A 2049
'72 TC Coupe' 'SLK' - 1950cc - Asleep - possible retirement project E.T.A 2049